For a relatively small investment, a variable speed pool pump can reduce pool pump energy use by 50% to 75%. The majority of the savings are derived from a variable speed pump’s ability to reduce the rpm of the motor, thus reducing energy use. A typical 1½-horsepower pool pump draws about 2,000 watts and runs at 3,450 rpm. Reducing the pump speed and flow has a tremendous impact on wattage draw due to the Pump Affinity Law.
If you reduce the pump speed from 3,450 rpm to 2,400 rpm (30% reduction in speed) the wattage drops from 2,000 watts to 593 watts (70% reduction in power). Replacing a single-speed pump with a modern variable speed pump is relatively quick and simple. In order to successfully complete the task, the installer must calculate the number of gallons of water in the pool and calibrate the new pump to circulate water at an appropriate rate.